1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use DBIx::Class::ResultSourceHandle;
16 use base qw/DBIx::Class/;
18 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
22 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
26 my $users_rs = $schema->resultset('User');
27 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
28 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
32 A ResultSet is an object which stores a set of conditions representing
33 a query. It is the backbone of DBIx::Class (i.e. the really
34 important/useful bit).
36 No SQL is executed on the database when a ResultSet is created, it
37 just stores all the conditions needed to create the query.
39 A basic ResultSet representing the data of an entire table is returned
40 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
41 L<Source|DBIx::Class::Manual::Glossary/Source> name.
43 my $users_rs = $schema->resultset('User');
45 A new ResultSet is returned from calling L</search> on an existing
46 ResultSet. The new one will contain all the conditions of the
47 original, plus any new conditions added in the C<search> call.
49 A ResultSet is also an iterator. L</next> is used to return all the
50 L<DBIx::Class::Row>s the ResultSet represents.
52 The query that the ResultSet represents is B<only> executed against
53 the database when these methods are called:
73 =head2 Chaining resultsets
75 Let's say you've got a query that needs to be run to return some data
76 to the user. But, you have an authorization system in place that
77 prevents certain users from seeing certain information. So, you want
78 to construct the basic query in one method, but add constraints to it in
83 my $request = $self->get_request; # Get a request object somehow.
84 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
86 my $cd_rs = $schema->resultset('CD')->search({
87 title => $request->param('title'),
88 year => $request->param('year'),
91 $self->apply_security_policy( $cd_rs );
96 sub apply_security_policy {
105 =head3 Resolving conditions and attributes
107 When a resultset is chained from another resultset, conditions and
108 attributes with the same keys need resolving.
110 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
111 into the existing ones from the original resultset.
113 The L</where>, L</having> attribute, and any search conditions are
114 merged with an SQL C<AND> to the existing condition from the original
117 All other attributes are overridden by any new ones supplied in the
120 =head2 Multiple queries
122 Since a resultset just defines a query, you can do all sorts of
123 things with it with the same object.
125 # Don't hit the DB yet.
126 my $cd_rs = $schema->resultset('CD')->search({
127 title => 'something',
131 # Each of these hits the DB individually.
132 my $count = $cd_rs->count;
133 my $most_recent = $cd_rs->get_column('date_released')->max();
134 my @records = $cd_rs->all;
136 And it's not just limited to SELECT statements.
142 $cd_rs->create({ artist => 'Fred' });
144 Which is the same as:
146 $schema->resultset('CD')->create({
147 title => 'something',
152 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
156 If a resultset is used in a numeric context it returns the L</count>.
157 However, if it is used in a booleand context it is always true. So if
158 you want to check if a resultset has any results use C<if $rs != 0>.
159 C<if $rs> will always be true.
167 =item Arguments: $source, \%$attrs
169 =item Return Value: $rs
173 The resultset constructor. Takes a source object (usually a
174 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
175 L</ATTRIBUTES> below). Does not perform any queries -- these are
176 executed as needed by the other methods.
178 Generally you won't need to construct a resultset manually. You'll
179 automatically get one from e.g. a L</search> called in scalar context:
181 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
183 IMPORTANT: If called on an object, proxies to new_result instead so
185 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
187 will return a CD object, not a ResultSet.
193 return $class->new_result(@_) if ref $class;
195 my ($source, $attrs) = @_;
196 $source = $source->handle
197 unless $source->isa('DBIx::Class::ResultSourceHandle');
198 $attrs = { %{$attrs||{}} };
200 if ($attrs->{page}) {
201 $attrs->{rows} ||= 10;
204 $attrs->{alias} ||= 'me';
206 # Creation of {} and bless separated to mitigate RH perl bug
207 # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
209 _source_handle => $source,
210 cond => $attrs->{where},
219 $attrs->{result_class} || $source->resolve->result_class
229 =item Arguments: $cond, \%attrs?
231 =item Return Value: $resultset (scalar context), @row_objs (list context)
235 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
236 my $new_rs = $cd_rs->search({ year => 2005 });
238 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
239 # year = 2005 OR year = 2004
241 If you need to pass in additional attributes but no additional condition,
242 call it as C<search(undef, \%attrs)>.
244 # "SELECT name, artistid FROM $artist_table"
245 my @all_artists = $schema->resultset('Artist')->search(undef, {
246 columns => [qw/name artistid/],
249 For a list of attributes that can be passed to C<search>, see
250 L</ATTRIBUTES>. For more examples of using this function, see
251 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
252 documentation for the first argument, see L<SQL::Abstract>.
254 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
260 my $rs = $self->search_rs( @_ );
261 return (wantarray ? $rs->all : $rs);
268 =item Arguments: $cond, \%attrs?
270 =item Return Value: $resultset
274 This method does the same exact thing as search() except it will
275 always return a resultset, even in list context.
283 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
284 my $our_attrs = { %{$self->{attrs}} };
285 my $having = delete $our_attrs->{having};
286 my $where = delete $our_attrs->{where};
290 my %safe = (alias => 1, cache => 1);
293 (@_ && defined($_[0])) # @_ == () or (undef)
295 (keys %$attrs # empty attrs or only 'safe' attrs
296 && List::Util::first { !$safe{$_} } keys %$attrs)
298 # no search, effectively just a clone
299 $rows = $self->get_cache;
302 my $new_attrs = { %{$our_attrs}, %{$attrs} };
304 # merge new attrs into inherited
305 foreach my $key (qw/join prefetch +select +as/) {
306 next unless exists $attrs->{$key};
307 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
312 (@_ == 1 || ref $_[0] eq "HASH")
314 (ref $_[0] eq 'HASH')
316 (keys %{ $_[0] } > 0)
324 ? $self->throw_exception("Odd number of arguments to search")
331 if (defined $where) {
332 $new_attrs->{where} = (
333 defined $new_attrs->{where}
336 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
337 } $where, $new_attrs->{where}
344 $new_attrs->{where} = (
345 defined $new_attrs->{where}
348 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
349 } $cond, $new_attrs->{where}
355 if (defined $having) {
356 $new_attrs->{having} = (
357 defined $new_attrs->{having}
360 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
361 } $having, $new_attrs->{having}
367 my $rs = (ref $self)->new($self->result_source, $new_attrs);
369 $rs->set_cache($rows);
374 =head2 search_literal
378 =item Arguments: $sql_fragment, @bind_values
380 =item Return Value: $resultset (scalar context), @row_objs (list context)
384 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
385 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
387 Pass a literal chunk of SQL to be added to the conditional part of the
390 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
391 only be used in that context. C<search_literal> is a convenience method.
392 It is equivalent to calling $schema->search(\[]), but if you want to ensure
393 columns are bound correctly, use C<search>.
395 Example of how to use C<search> instead of C<search_literal>
397 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
398 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
401 See L<DBIx::Class::Manual::Cookbook/Searching> and
402 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
403 require C<search_literal>.
408 my ($self, $sql, @bind) = @_;
409 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ]);
416 =item Arguments: @values | \%cols, \%attrs?
418 =item Return Value: $row_object | undef
422 Finds a row based on its primary key or unique constraint. For example, to find
423 a row by its primary key:
425 my $cd = $schema->resultset('CD')->find(5);
427 You can also find a row by a specific unique constraint using the C<key>
428 attribute. For example:
430 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
431 key => 'cd_artist_title'
434 Additionally, you can specify the columns explicitly by name:
436 my $cd = $schema->resultset('CD')->find(
438 artist => 'Massive Attack',
439 title => 'Mezzanine',
441 { key => 'cd_artist_title' }
444 If the C<key> is specified as C<primary>, it searches only on the primary key.
446 If no C<key> is specified, it searches on all unique constraints defined on the
447 source for which column data is provided, including the primary key.
449 If your table does not have a primary key, you B<must> provide a value for the
450 C<key> attribute matching one of the unique constraints on the source.
452 In addition to C<key>, L</find> recognizes and applies standard
453 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
455 Note: If your query does not return only one row, a warning is generated:
457 Query returned more than one row
459 See also L</find_or_create> and L</update_or_create>. For information on how to
460 declare unique constraints, see
461 L<DBIx::Class::ResultSource/add_unique_constraint>.
467 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
469 # Default to the primary key, but allow a specific key
470 my @cols = exists $attrs->{key}
471 ? $self->result_source->unique_constraint_columns($attrs->{key})
472 : $self->result_source->primary_columns;
473 $self->throw_exception(
474 "Can't find unless a primary key is defined or unique constraint is specified"
477 # Parse out a hashref from input
479 if (ref $_[0] eq 'HASH') {
480 $input_query = { %{$_[0]} };
482 elsif (@_ == @cols) {
484 @{$input_query}{@cols} = @_;
487 # Compatibility: Allow e.g. find(id => $value)
488 carp "Find by key => value deprecated; please use a hashref instead";
492 my (%related, $info);
494 KEY: foreach my $key (keys %$input_query) {
495 if (ref($input_query->{$key})
496 && ($info = $self->result_source->relationship_info($key))) {
497 my $val = delete $input_query->{$key};
498 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
499 my $rel_q = $self->result_source->resolve_condition(
500 $info->{cond}, $val, $key
502 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
503 @related{keys %$rel_q} = values %$rel_q;
506 if (my @keys = keys %related) {
507 @{$input_query}{@keys} = values %related;
511 # Build the final query: Default to the disjunction of the unique queries,
512 # but allow the input query in case the ResultSet defines the query or the
513 # user is abusing find
514 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
516 if (exists $attrs->{key}) {
517 my @unique_cols = $self->result_source->unique_constraint_columns($attrs->{key});
518 my $unique_query = $self->_build_unique_query($input_query, \@unique_cols);
519 $query = $self->_add_alias($unique_query, $alias);
522 my @unique_queries = $self->_unique_queries($input_query, $attrs);
523 $query = @unique_queries
524 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
525 : $self->_add_alias($input_query, $alias);
530 my $rs = $self->search($query, $attrs);
531 if (keys %{$rs->_resolved_attrs->{collapse}}) {
533 carp "Query returned more than one row" if $rs->next;
541 if (keys %{$self->_resolved_attrs->{collapse}}) {
542 my $rs = $self->search($query);
544 carp "Query returned more than one row" if $rs->next;
548 return $self->single($query);
555 # Add the specified alias to the specified query hash. A copy is made so the
556 # original query is not modified.
559 my ($self, $query, $alias) = @_;
561 my %aliased = %$query;
562 foreach my $col (grep { ! m/\./ } keys %aliased) {
563 $aliased{"$alias.$col"} = delete $aliased{$col};
571 # Build a list of queries which satisfy unique constraints.
573 sub _unique_queries {
574 my ($self, $query, $attrs) = @_;
576 my @constraint_names = exists $attrs->{key}
578 : $self->result_source->unique_constraint_names;
580 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
581 my $num_where = scalar keys %$where;
584 foreach my $name (@constraint_names) {
585 my @unique_cols = $self->result_source->unique_constraint_columns($name);
586 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
588 my $num_cols = scalar @unique_cols;
589 my $num_query = scalar keys %$unique_query;
591 my $total = $num_query + $num_where;
592 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
593 # The query is either unique on its own or is unique in combination with
594 # the existing where clause
595 push @unique_queries, $unique_query;
599 return @unique_queries;
602 # _build_unique_query
604 # Constrain the specified query hash based on the specified column names.
606 sub _build_unique_query {
607 my ($self, $query, $unique_cols) = @_;
610 map { $_ => $query->{$_} }
611 grep { exists $query->{$_} }
616 =head2 search_related
620 =item Arguments: $rel, $cond, \%attrs?
622 =item Return Value: $new_resultset
626 $new_rs = $cd_rs->search_related('artist', {
630 Searches the specified relationship, optionally specifying a condition and
631 attributes for matching records. See L</ATTRIBUTES> for more information.
636 return shift->related_resultset(shift)->search(@_);
639 =head2 search_related_rs
641 This method works exactly the same as search_related, except that
642 it guarantees a restultset, even in list context.
646 sub search_related_rs {
647 return shift->related_resultset(shift)->search_rs(@_);
654 =item Arguments: none
656 =item Return Value: $cursor
660 Returns a storage-driven cursor to the given resultset. See
661 L<DBIx::Class::Cursor> for more information.
668 my $attrs = { %{$self->_resolved_attrs} };
669 return $self->{cursor}
670 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
671 $attrs->{where},$attrs);
678 =item Arguments: $cond?
680 =item Return Value: $row_object?
684 my $cd = $schema->resultset('CD')->single({ year => 2001 });
686 Inflates the first result without creating a cursor if the resultset has
687 any records in it; if not returns nothing. Used by L</find> as a lean version of
690 While this method can take an optional search condition (just like L</search>)
691 being a fast-code-path it does not recognize search attributes. If you need to
692 add extra joins or similar, call L</search> and then chain-call L</single> on the
693 L<DBIx::Class::ResultSet> returned.
699 As of 0.08100, this method enforces the assumption that the preceeding
700 query returns only one row. If more than one row is returned, you will receive
703 Query returned more than one row
705 In this case, you should be using L</first> or L</find> instead, or if you really
706 know what you are doing, use the L</rows> attribute to explicitly limit the size
714 my ($self, $where) = @_;
716 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
719 my $attrs = { %{$self->_resolved_attrs} };
721 if (defined $attrs->{where}) {
724 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
725 $where, delete $attrs->{where} ]
728 $attrs->{where} = $where;
732 # XXX: Disabled since it doesn't infer uniqueness in all cases
733 # unless ($self->_is_unique_query($attrs->{where})) {
734 # carp "Query not guaranteed to return a single row"
735 # . "; please declare your unique constraints or use search instead";
738 my @data = $self->result_source->storage->select_single(
739 $attrs->{from}, $attrs->{select},
740 $attrs->{where}, $attrs
743 return (@data ? ($self->_construct_object(@data))[0] : undef);
748 # Try to determine if the specified query is guaranteed to be unique, based on
749 # the declared unique constraints.
751 sub _is_unique_query {
752 my ($self, $query) = @_;
754 my $collapsed = $self->_collapse_query($query);
755 my $alias = $self->{attrs}{alias};
757 foreach my $name ($self->result_source->unique_constraint_names) {
758 my @unique_cols = map {
760 } $self->result_source->unique_constraint_columns($name);
762 # Count the values for each unique column
763 my %seen = map { $_ => 0 } @unique_cols;
765 foreach my $key (keys %$collapsed) {
766 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
767 next unless exists $seen{$aliased}; # Additional constraints are okay
768 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
771 # If we get 0 or more than 1 value for a column, it's not necessarily unique
772 return 1 unless grep { $_ != 1 } values %seen;
780 # Recursively collapse the query, accumulating values for each column.
782 sub _collapse_query {
783 my ($self, $query, $collapsed) = @_;
787 if (ref $query eq 'ARRAY') {
788 foreach my $subquery (@$query) {
789 next unless ref $subquery; # -or
790 # warn "ARRAY: " . Dumper $subquery;
791 $collapsed = $self->_collapse_query($subquery, $collapsed);
794 elsif (ref $query eq 'HASH') {
795 if (keys %$query and (keys %$query)[0] eq '-and') {
796 foreach my $subquery (@{$query->{-and}}) {
797 # warn "HASH: " . Dumper $subquery;
798 $collapsed = $self->_collapse_query($subquery, $collapsed);
802 # warn "LEAF: " . Dumper $query;
803 foreach my $col (keys %$query) {
804 my $value = $query->{$col};
805 $collapsed->{$col}{$value}++;
817 =item Arguments: $cond?
819 =item Return Value: $resultsetcolumn
823 my $max_length = $rs->get_column('length')->max;
825 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
830 my ($self, $column) = @_;
831 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
839 =item Arguments: $cond, \%attrs?
841 =item Return Value: $resultset (scalar context), @row_objs (list context)
845 # WHERE title LIKE '%blue%'
846 $cd_rs = $rs->search_like({ title => '%blue%'});
848 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
849 that this is simply a convenience method retained for ex Class::DBI users.
850 You most likely want to use L</search> with specific operators.
852 For more information, see L<DBIx::Class::Manual::Cookbook>.
858 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
859 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
860 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
861 return $class->search($query, { %$attrs });
868 =item Arguments: $first, $last
870 =item Return Value: $resultset (scalar context), @row_objs (list context)
874 Returns a resultset or object list representing a subset of elements from the
875 resultset slice is called on. Indexes are from 0, i.e., to get the first
878 my ($one, $two, $three) = $rs->slice(0, 2);
883 my ($self, $min, $max) = @_;
884 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
885 $attrs->{offset} = $self->{attrs}{offset} || 0;
886 $attrs->{offset} += $min;
887 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
888 return $self->search(undef(), $attrs);
889 #my $slice = (ref $self)->new($self->result_source, $attrs);
890 #return (wantarray ? $slice->all : $slice);
897 =item Arguments: none
899 =item Return Value: $result?
903 Returns the next element in the resultset (C<undef> is there is none).
905 Can be used to efficiently iterate over records in the resultset:
907 my $rs = $schema->resultset('CD')->search;
908 while (my $cd = $rs->next) {
912 Note that you need to store the resultset object, and call C<next> on it.
913 Calling C<< resultset('Table')->next >> repeatedly will always return the
914 first record from the resultset.
920 if (my $cache = $self->get_cache) {
921 $self->{all_cache_position} ||= 0;
922 return $cache->[$self->{all_cache_position}++];
924 if ($self->{attrs}{cache}) {
925 $self->{all_cache_position} = 1;
926 return ($self->all)[0];
928 if ($self->{stashed_objects}) {
929 my $obj = shift(@{$self->{stashed_objects}});
930 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
934 exists $self->{stashed_row}
935 ? @{delete $self->{stashed_row}}
936 : $self->cursor->next
938 return undef unless (@row);
939 my ($row, @more) = $self->_construct_object(@row);
940 $self->{stashed_objects} = \@more if @more;
944 sub _construct_object {
945 my ($self, @row) = @_;
946 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
947 my @new = $self->result_class->inflate_result($self->result_source, @$info);
948 @new = $self->{_attrs}{record_filter}->(@new)
949 if exists $self->{_attrs}{record_filter};
953 sub _collapse_result {
954 my ($self, $as_proto, $row) = @_;
958 # 'foo' => [ undef, 'foo' ]
959 # 'foo.bar' => [ 'foo', 'bar' ]
960 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
962 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
964 my %collapse = %{$self->{_attrs}{collapse}||{}};
968 # if we're doing collapsing (has_many prefetch) we need to grab records
969 # until the PK changes, so fill @pri_index. if not, we leave it empty so
970 # we know we don't have to bother.
972 # the reason for not using the collapse stuff directly is because if you
973 # had for e.g. two artists in a row with no cds, the collapse info for
974 # both would be NULL (undef) so you'd lose the second artist
976 # store just the index so we can check the array positions from the row
977 # without having to contruct the full hash
979 if (keys %collapse) {
980 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
981 foreach my $i (0 .. $#construct_as) {
982 next if defined($construct_as[$i][0]); # only self table
983 if (delete $pri{$construct_as[$i][1]}) {
984 push(@pri_index, $i);
986 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
990 # no need to do an if, it'll be empty if @pri_index is empty anyway
992 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
996 do { # no need to check anything at the front, we always want the first row
1000 foreach my $this_as (@construct_as) {
1001 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1004 push(@const_rows, \%const);
1006 } until ( # no pri_index => no collapse => drop straight out
1009 do { # get another row, stash it, drop out if different PK
1011 @copy = $self->cursor->next;
1012 $self->{stashed_row} = \@copy;
1014 # last thing in do block, counts as true if anything doesn't match
1016 # check xor defined first for NULL vs. NOT NULL then if one is
1017 # defined the other must be so check string equality
1020 (defined $pri_vals{$_} ^ defined $copy[$_])
1021 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1026 my $alias = $self->{attrs}{alias};
1033 foreach my $const (@const_rows) {
1034 scalar @const_keys or do {
1035 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1037 foreach my $key (@const_keys) {
1040 my @parts = split(/\./, $key);
1042 my $data = $const->{$key};
1043 foreach my $p (@parts) {
1044 $target = $target->[1]->{$p} ||= [];
1046 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1047 # collapsing at this point and on final part
1048 my $pos = $collapse_pos{$cur};
1049 CK: foreach my $ck (@ckey) {
1050 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1051 $collapse_pos{$cur} = $data;
1052 delete @collapse_pos{ # clear all positioning for sub-entries
1053 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1060 if (exists $collapse{$cur}) {
1061 $target = $target->[-1];
1064 $target->[0] = $data;
1066 $info->[0] = $const->{$key};
1074 =head2 result_source
1078 =item Arguments: $result_source?
1080 =item Return Value: $result_source
1084 An accessor for the primary ResultSource object from which this ResultSet
1091 =item Arguments: $result_class?
1093 =item Return Value: $result_class
1097 An accessor for the class to use when creating row objects. Defaults to
1098 C<< result_source->result_class >> - which in most cases is the name of the
1099 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1104 my ($self, $result_class) = @_;
1105 if ($result_class) {
1106 $self->ensure_class_loaded($result_class);
1107 $self->_result_class($result_class);
1109 $self->_result_class;
1116 =item Arguments: $cond, \%attrs??
1118 =item Return Value: $count
1122 Performs an SQL C<COUNT> with the same query as the resultset was built
1123 with to find the number of elements. If passed arguments, does a search
1124 on the resultset and counts the results of that.
1126 Note: When using C<count> with C<group_by>, L<DBIx::Class> emulates C<GROUP BY>
1127 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
1128 not support C<DISTINCT> with multiple columns. If you are using such a
1129 database, you should only use columns from the main table in your C<group_by>
1136 return $self->search(@_)->count if @_ and defined $_[0];
1137 return scalar @{ $self->get_cache } if $self->get_cache;
1138 my $count = $self->_count;
1139 return 0 unless $count;
1141 # need to take offset from resolved attrs
1143 $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
1144 $count = $self->{attrs}{rows} if
1145 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
1146 $count = 0 if ($count < 0);
1150 sub _count { # Separated out so pager can get the full count
1152 my $select = { count => '*' };
1154 my $attrs = { %{$self->_resolved_attrs} };
1155 if (my $group_by = delete $attrs->{group_by}) {
1156 delete $attrs->{having};
1157 my @distinct = (ref $group_by ? @$group_by : ($group_by));
1158 # todo: try CONCAT for multi-column pk
1159 my @pk = $self->result_source->primary_columns;
1161 my $alias = $attrs->{alias};
1162 foreach my $column (@distinct) {
1163 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
1164 @distinct = ($column);
1170 $select = { count => { distinct => \@distinct } };
1173 $attrs->{select} = $select;
1174 $attrs->{as} = [qw/count/];
1176 # offset, order by and page are not needed to count. record_filter is cdbi
1177 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
1179 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1180 my ($count) = $tmp_rs->cursor->next;
1188 =head2 count_literal
1192 =item Arguments: $sql_fragment, @bind_values
1194 =item Return Value: $count
1198 Counts the results in a literal query. Equivalent to calling L</search_literal>
1199 with the passed arguments, then L</count>.
1203 sub count_literal { shift->search_literal(@_)->count; }
1209 =item Arguments: none
1211 =item Return Value: @objects
1215 Returns all elements in the resultset. Called implicitly if the resultset
1216 is returned in list context.
1223 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1226 return @{ $self->get_cache } if $self->get_cache;
1230 # TODO: don't call resolve here
1231 if (keys %{$self->_resolved_attrs->{collapse}}) {
1232 # if ($self->{attrs}{prefetch}) {
1233 # Using $self->cursor->all is really just an optimisation.
1234 # If we're collapsing has_many prefetches it probably makes
1235 # very little difference, and this is cleaner than hacking
1236 # _construct_object to survive the approach
1237 my @row = $self->cursor->next;
1239 push(@obj, $self->_construct_object(@row));
1240 @row = (exists $self->{stashed_row}
1241 ? @{delete $self->{stashed_row}}
1242 : $self->cursor->next);
1245 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1248 $self->set_cache(\@obj) if $self->{attrs}{cache};
1256 =item Arguments: none
1258 =item Return Value: $self
1262 Resets the resultset's cursor, so you can iterate through the elements again.
1268 delete $self->{_attrs} if exists $self->{_attrs};
1269 $self->{all_cache_position} = 0;
1270 $self->cursor->reset;
1278 =item Arguments: none
1280 =item Return Value: $object?
1284 Resets the resultset and returns an object for the first result (if the
1285 resultset returns anything).
1290 return $_[0]->reset->next;
1293 # _cond_for_update_delete
1295 # update/delete require the condition to be modified to handle
1296 # the differing SQL syntax available. This transforms the $self->{cond}
1297 # appropriately, returning the new condition.
1299 sub _cond_for_update_delete {
1300 my ($self, $full_cond) = @_;
1303 $full_cond ||= $self->{cond};
1304 # No-op. No condition, we're updating/deleting everything
1305 return $cond unless ref $full_cond;
1307 if (ref $full_cond eq 'ARRAY') {
1311 foreach my $key (keys %{$_}) {
1313 $hash{$1} = $_->{$key};
1319 elsif (ref $full_cond eq 'HASH') {
1320 if ((keys %{$full_cond})[0] eq '-and') {
1323 my @cond = @{$full_cond->{-and}};
1324 for (my $i = 0; $i < @cond; $i++) {
1325 my $entry = $cond[$i];
1328 if (ref $entry eq 'HASH') {
1329 $hash = $self->_cond_for_update_delete($entry);
1332 $entry =~ /([^.]+)$/;
1333 $hash->{$1} = $cond[++$i];
1336 push @{$cond->{-and}}, $hash;
1340 foreach my $key (keys %{$full_cond}) {
1342 $cond->{$1} = $full_cond->{$key};
1347 $self->throw_exception(
1348 "Can't update/delete on resultset with condition unless hash or array"
1360 =item Arguments: \%values
1362 =item Return Value: $storage_rv
1366 Sets the specified columns in the resultset to the supplied values in a
1367 single query. Return value will be true if the update succeeded or false
1368 if no records were updated; exact type of success value is storage-dependent.
1373 my ($self, $values) = @_;
1374 $self->throw_exception("Values for update must be a hash")
1375 unless ref $values eq 'HASH';
1377 carp( 'WARNING! Currently $rs->update() does not generate proper SQL'
1378 . ' on joined resultsets, and may affect rows well outside of the'
1379 . ' contents of $rs. Use at your own risk' )
1380 if ( $self->{attrs}{seen_join} );
1382 my $cond = $self->_cond_for_update_delete;
1384 return $self->result_source->storage->update(
1385 $self->result_source, $values, $cond
1393 =item Arguments: \%values
1395 =item Return Value: 1
1399 Fetches all objects and updates them one at a time. Note that C<update_all>
1400 will run DBIC cascade triggers, while L</update> will not.
1405 my ($self, $values) = @_;
1406 $self->throw_exception("Values for update must be a hash")
1407 unless ref $values eq 'HASH';
1408 foreach my $obj ($self->all) {
1409 $obj->set_columns($values)->update;
1418 =item Arguments: none
1420 =item Return Value: 1
1424 Deletes the contents of the resultset from its result source. Note that this
1425 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1426 to run. See also L<DBIx::Class::Row/delete>.
1428 delete may not generate correct SQL for a query with joins or a resultset
1429 chained from a related resultset. In this case it will generate a warning:-
1431 WARNING! Currently $rs->delete() does not generate proper SQL on
1432 joined resultsets, and may delete rows well outside of the contents
1433 of $rs. Use at your own risk
1435 In these cases you may find that delete_all is more appropriate, or you
1436 need to respecify your query in a way that can be expressed without a join.
1442 $self->throw_exception("Delete should not be passed any arguments")
1444 carp( 'WARNING! Currently $rs->delete() does not generate proper SQL'
1445 . ' on joined resultsets, and may delete rows well outside of the'
1446 . ' contents of $rs. Use at your own risk' )
1447 if ( $self->{attrs}{seen_join} );
1448 my $cond = $self->_cond_for_update_delete;
1450 $self->result_source->storage->delete($self->result_source, $cond);
1458 =item Arguments: none
1460 =item Return Value: 1
1464 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1465 will run DBIC cascade triggers, while L</delete> will not.
1471 $_->delete for $self->all;
1479 =item Arguments: \@data;
1483 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1484 For the arrayref of hashrefs style each hashref should be a structure suitable
1485 forsubmitting to a $resultset->create(...) method.
1487 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1488 to insert the data, as this is a faster method.
1490 Otherwise, each set of data is inserted into the database using
1491 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1492 objects is returned.
1494 Example: Assuming an Artist Class that has many CDs Classes relating:
1496 my $Artist_rs = $schema->resultset("Artist");
1498 ## Void Context Example
1499 $Artist_rs->populate([
1500 { artistid => 4, name => 'Manufactured Crap', cds => [
1501 { title => 'My First CD', year => 2006 },
1502 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1505 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1506 { title => 'My parents sold me to a record company' ,year => 2005 },
1507 { title => 'Why Am I So Ugly?', year => 2006 },
1508 { title => 'I Got Surgery and am now Popular', year => 2007 }
1513 ## Array Context Example
1514 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1515 { name => "Artist One"},
1516 { name => "Artist Two"},
1517 { name => "Artist Three", cds=> [
1518 { title => "First CD", year => 2007},
1519 { title => "Second CD", year => 2008},
1523 print $ArtistOne->name; ## response is 'Artist One'
1524 print $ArtistThree->cds->count ## reponse is '2'
1526 For the arrayref of arrayrefs style, the first element should be a list of the
1527 fieldsnames to which the remaining elements are rows being inserted. For
1530 $Arstist_rs->populate([
1531 [qw/artistid name/],
1532 [100, 'A Formally Unknown Singer'],
1533 [101, 'A singer that jumped the shark two albums ago'],
1534 [102, 'An actually cool singer.'],
1537 Please note an important effect on your data when choosing between void and
1538 wantarray context. Since void context goes straight to C<insert_bulk> in
1539 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1540 c<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1541 create primary keys for you, you will find that your PKs are empty. In this
1542 case you will have to use the wantarray context in order to create those
1548 my $self = shift @_;
1549 my $data = ref $_[0][0] eq 'HASH'
1550 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1551 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1553 if(defined wantarray) {
1555 foreach my $item (@$data) {
1556 push(@created, $self->create($item));
1560 my ($first, @rest) = @$data;
1562 my @names = grep {!ref $first->{$_}} keys %$first;
1563 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1564 my @pks = $self->result_source->primary_columns;
1566 ## do the belongs_to relationships
1567 foreach my $index (0..$#$data) {
1568 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1569 my @ret = $self->populate($data);
1573 foreach my $rel (@rels) {
1574 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1575 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1576 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1577 my $related = $result->result_source->resolve_condition(
1578 $result->result_source->relationship_info($reverse)->{cond},
1583 delete $data->[$index]->{$rel};
1584 $data->[$index] = {%{$data->[$index]}, %$related};
1586 push @names, keys %$related if $index == 0;
1590 ## do bulk insert on current row
1591 my @values = map { [ @$_{@names} ] } @$data;
1593 $self->result_source->storage->insert_bulk(
1594 $self->result_source,
1599 ## do the has_many relationships
1600 foreach my $item (@$data) {
1602 foreach my $rel (@rels) {
1603 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1605 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1606 || $self->throw_exception('Cannot find the relating object.');
1608 my $child = $parent->$rel;
1610 my $related = $child->result_source->resolve_condition(
1611 $parent->result_source->relationship_info($rel)->{cond},
1616 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1617 my @populate = map { {%$_, %$related} } @rows_to_add;
1619 $child->populate( \@populate );
1625 =head2 _normalize_populate_args ($args)
1627 Private method used by L</populate> to normalize its incoming arguments. Factored
1628 out in case you want to subclass and accept new argument structures to the
1629 L</populate> method.
1633 sub _normalize_populate_args {
1634 my ($self, $data) = @_;
1635 my @names = @{shift(@$data)};
1636 my @results_to_create;
1637 foreach my $datum (@$data) {
1638 my %result_to_create;
1639 foreach my $index (0..$#names) {
1640 $result_to_create{$names[$index]} = $$datum[$index];
1642 push @results_to_create, \%result_to_create;
1644 return \@results_to_create;
1651 =item Arguments: none
1653 =item Return Value: $pager
1657 Return Value a L<Data::Page> object for the current resultset. Only makes
1658 sense for queries with a C<page> attribute.
1660 To get the full count of entries for a paged resultset, call
1661 C<total_entries> on the L<Data::Page> object.
1667 my $attrs = $self->{attrs};
1668 $self->throw_exception("Can't create pager for non-paged rs")
1669 unless $self->{attrs}{page};
1670 $attrs->{rows} ||= 10;
1671 return $self->{pager} ||= Data::Page->new(
1672 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1679 =item Arguments: $page_number
1681 =item Return Value: $rs
1685 Returns a resultset for the $page_number page of the resultset on which page
1686 is called, where each page contains a number of rows equal to the 'rows'
1687 attribute set on the resultset (10 by default).
1692 my ($self, $page) = @_;
1693 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1700 =item Arguments: \%vals
1702 =item Return Value: $rowobject
1706 Creates a new row object in the resultset's result class and returns
1707 it. The row is not inserted into the database at this point, call
1708 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1709 will tell you whether the row object has been inserted or not.
1711 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1716 my ($self, $values) = @_;
1717 $self->throw_exception( "new_result needs a hash" )
1718 unless (ref $values eq 'HASH');
1721 my $alias = $self->{attrs}{alias};
1724 defined $self->{cond}
1725 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1727 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1728 $new{-from_resultset} = [ keys %new ] if keys %new;
1730 $self->throw_exception(
1731 "Can't abstract implicit construct, condition not a hash"
1732 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1734 my $collapsed_cond = (
1736 ? $self->_collapse_cond($self->{cond})
1740 # precendence must be given to passed values over values inherited from
1741 # the cond, so the order here is important.
1742 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1743 while( my($col,$value) = each %implied ){
1744 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1745 $new{$col} = $value->{'='};
1748 $new{$col} = $value if $self->_is_deterministic_value($value);
1754 %{ $self->_remove_alias($values, $alias) },
1755 -source_handle => $self->_source_handle,
1756 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1759 return $self->result_class->new(\%new);
1762 # _is_deterministic_value
1764 # Make an effor to strip non-deterministic values from the condition,
1765 # to make sure new_result chokes less
1767 sub _is_deterministic_value {
1770 my $ref_type = ref $value;
1771 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1772 return 1 if Scalar::Util::blessed($value);
1778 # Recursively collapse the condition.
1780 sub _collapse_cond {
1781 my ($self, $cond, $collapsed) = @_;
1785 if (ref $cond eq 'ARRAY') {
1786 foreach my $subcond (@$cond) {
1787 next unless ref $subcond; # -or
1788 # warn "ARRAY: " . Dumper $subcond;
1789 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1792 elsif (ref $cond eq 'HASH') {
1793 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1794 foreach my $subcond (@{$cond->{-and}}) {
1795 # warn "HASH: " . Dumper $subcond;
1796 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1800 # warn "LEAF: " . Dumper $cond;
1801 foreach my $col (keys %$cond) {
1802 my $value = $cond->{$col};
1803 $collapsed->{$col} = $value;
1813 # Remove the specified alias from the specified query hash. A copy is made so
1814 # the original query is not modified.
1817 my ($self, $query, $alias) = @_;
1819 my %orig = %{ $query || {} };
1822 foreach my $key (keys %orig) {
1824 $unaliased{$key} = $orig{$key};
1827 $unaliased{$1} = $orig{$key}
1828 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1834 =head2 as_query (EXPERIMENTAL)
1838 =item Arguments: none
1840 =item Return Value: \[ $sql, @bind ]
1844 Returns the SQL query and bind vars associated with the invocant.
1846 This is generally used as the RHS for a subquery.
1848 B<NOTE>: This feature is still experimental.
1852 sub as_query { return shift->cursor->as_query(@_) }
1858 =item Arguments: \%vals, \%attrs?
1860 =item Return Value: $rowobject
1864 my $artist = $schema->resultset('Artist')->find_or_new(
1865 { artist => 'fred' }, { key => 'artists' });
1867 $cd->cd_to_producer->find_or_new({ producer => $producer },
1868 { key => 'primary });
1870 Find an existing record from this resultset, based on its primary
1871 key, or a unique constraint. If none exists, instantiate a new result
1872 object and return it. The object will not be saved into your storage
1873 until you call L<DBIx::Class::Row/insert> on it.
1875 You most likely want this method when looking for existing rows using
1876 a unique constraint that is not the primary key, or looking for
1879 If you want objects to be saved immediately, use L</find_or_create> instead.
1881 B<Note>: C<find_or_new> is probably not what you want when creating a
1882 new row in a table that uses primary keys supplied by the
1883 database. Passing in a primary key column with a value of I<undef>
1884 will cause L</find> to attempt to search for a row with a value of
1891 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1892 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1893 my $exists = $self->find($hash, $attrs);
1894 return defined $exists ? $exists : $self->new_result($hash);
1901 =item Arguments: \%vals
1903 =item Return Value: a L<DBIx::Class::Row> $object
1907 Attempt to create a single new row or a row with multiple related rows
1908 in the table represented by the resultset (and related tables). This
1909 will not check for duplicate rows before inserting, use
1910 L</find_or_create> to do that.
1912 To create one row for this resultset, pass a hashref of key/value
1913 pairs representing the columns of the table and the values you wish to
1914 store. If the appropriate relationships are set up, foreign key fields
1915 can also be passed an object representing the foreign row, and the
1916 value will be set to its primary key.
1918 To create related objects, pass a hashref for the value if the related
1919 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
1920 and use the name of the relationship as the key. (NOT the name of the field,
1921 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
1922 of hashrefs containing the data for each of the rows to create in the foreign
1923 tables, again using the relationship name as the key.
1925 Instead of hashrefs of plain related data (key/value pairs), you may
1926 also pass new or inserted objects. New objects (not inserted yet, see
1927 L</new>), will be inserted into their appropriate tables.
1929 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1931 Example of creating a new row.
1933 $person_rs->create({
1934 name=>"Some Person",
1935 email=>"somebody@someplace.com"
1938 Example of creating a new row and also creating rows in a related C<has_many>
1939 or C<has_one> resultset. Note Arrayref.
1942 { artistid => 4, name => 'Manufactured Crap', cds => [
1943 { title => 'My First CD', year => 2006 },
1944 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1949 Example of creating a new row and also creating a row in a related
1950 C<belongs_to>resultset. Note Hashref.
1953 title=>"Music for Silly Walks",
1956 name=>"Silly Musician",
1963 my ($self, $attrs) = @_;
1964 $self->throw_exception( "create needs a hashref" )
1965 unless ref $attrs eq 'HASH';
1966 return $self->new_result($attrs)->insert;
1969 =head2 find_or_create
1973 =item Arguments: \%vals, \%attrs?
1975 =item Return Value: $rowobject
1979 $cd->cd_to_producer->find_or_create({ producer => $producer },
1980 { key => 'primary });
1982 Tries to find a record based on its primary key or unique constraints; if none
1983 is found, creates one and returns that instead.
1985 my $cd = $schema->resultset('CD')->find_or_create({
1987 artist => 'Massive Attack',
1988 title => 'Mezzanine',
1992 Also takes an optional C<key> attribute, to search by a specific key or unique
1993 constraint. For example:
1995 my $cd = $schema->resultset('CD')->find_or_create(
1997 artist => 'Massive Attack',
1998 title => 'Mezzanine',
2000 { key => 'cd_artist_title' }
2003 B<Note>: Because find_or_create() reads from the database and then
2004 possibly inserts based on the result, this method is subject to a race
2005 condition. Another process could create a record in the table after
2006 the find has completed and before the create has started. To avoid
2007 this problem, use find_or_create() inside a transaction.
2009 B<Note>: C<find_or_create> is probably not what you want when creating
2010 a new row in a table that uses primary keys supplied by the
2011 database. Passing in a primary key column with a value of I<undef>
2012 will cause L</find> to attempt to search for a row with a value of
2015 See also L</find> and L</update_or_create>. For information on how to declare
2016 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2020 sub find_or_create {
2022 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2023 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2024 my $exists = $self->find($hash, $attrs);
2025 return defined $exists ? $exists : $self->create($hash);
2028 =head2 update_or_create
2032 =item Arguments: \%col_values, { key => $unique_constraint }?
2034 =item Return Value: $rowobject
2038 $resultset->update_or_create({ col => $val, ... });
2040 First, searches for an existing row matching one of the unique constraints
2041 (including the primary key) on the source of this resultset. If a row is
2042 found, updates it with the other given column values. Otherwise, creates a new
2045 Takes an optional C<key> attribute to search on a specific unique constraint.
2048 # In your application
2049 my $cd = $schema->resultset('CD')->update_or_create(
2051 artist => 'Massive Attack',
2052 title => 'Mezzanine',
2055 { key => 'cd_artist_title' }
2058 $cd->cd_to_producer->update_or_create({
2059 producer => $producer,
2066 If no C<key> is specified, it searches on all unique constraints defined on the
2067 source, including the primary key.
2069 If the C<key> is specified as C<primary>, it searches only on the primary key.
2071 See also L</find> and L</find_or_create>. For information on how to declare
2072 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2074 B<Note>: C<update_or_create> is probably not what you want when
2075 looking for a row in a table that uses primary keys supplied by the
2076 database, unless you actually have a key value. Passing in a primary
2077 key column with a value of I<undef> will cause L</find> to attempt to
2078 search for a row with a value of I<NULL>.
2082 sub update_or_create {
2084 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2085 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2087 my $row = $self->find($cond, $attrs);
2089 $row->update($cond);
2093 return $self->create($cond);
2100 =item Arguments: none
2102 =item Return Value: \@cache_objects?
2106 Gets the contents of the cache for the resultset, if the cache is set.
2108 The cache is populated either by using the L</prefetch> attribute to
2109 L</search> or by calling L</set_cache>.
2121 =item Arguments: \@cache_objects
2123 =item Return Value: \@cache_objects
2127 Sets the contents of the cache for the resultset. Expects an arrayref
2128 of objects of the same class as those produced by the resultset. Note that
2129 if the cache is set the resultset will return the cached objects rather
2130 than re-querying the database even if the cache attr is not set.
2132 The contents of the cache can also be populated by using the
2133 L</prefetch> attribute to L</search>.
2138 my ( $self, $data ) = @_;
2139 $self->throw_exception("set_cache requires an arrayref")
2140 if defined($data) && (ref $data ne 'ARRAY');
2141 $self->{all_cache} = $data;
2148 =item Arguments: none
2150 =item Return Value: []
2154 Clears the cache for the resultset.
2159 shift->set_cache(undef);
2162 =head2 related_resultset
2166 =item Arguments: $relationship_name
2168 =item Return Value: $resultset
2172 Returns a related resultset for the supplied relationship name.
2174 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2178 sub related_resultset {
2179 my ($self, $rel) = @_;
2181 $self->{related_resultsets} ||= {};
2182 return $self->{related_resultsets}{$rel} ||= do {
2183 my $rel_obj = $self->result_source->relationship_info($rel);
2185 $self->throw_exception(
2186 "search_related: result source '" . $self->result_source->source_name .
2187 "' has no such relationship $rel")
2190 my ($from,$seen) = $self->_resolve_from($rel);
2192 my $join_count = $seen->{$rel};
2193 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2195 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2196 my %attrs = %{$self->{attrs}||{}};
2197 delete @attrs{qw(result_class alias)};
2201 if (my $cache = $self->get_cache) {
2202 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2203 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2208 my $rel_source = $self->result_source->related_source($rel);
2212 # The reason we do this now instead of passing the alias to the
2213 # search_rs below is that if you wrap/overload resultset on the
2214 # source you need to know what alias it's -going- to have for things
2215 # to work sanely (e.g. RestrictWithObject wants to be able to add
2216 # extra query restrictions, and these may need to be $alias.)
2218 my $attrs = $rel_source->resultset_attributes;
2219 local $attrs->{alias} = $alias;
2221 $rel_source->resultset
2229 where => $self->{cond},
2234 $new->set_cache($new_cache) if $new_cache;
2239 =head2 current_source_alias
2243 =item Arguments: none
2245 =item Return Value: $source_alias
2249 Returns the current table alias for the result source this resultset is built
2250 on, that will be used in the SQL query. Usually it is C<me>.
2252 Currently the source alias that refers to the result set returned by a
2253 L</search>/L</find> family method depends on how you got to the resultset: it's
2254 C<me> by default, but eg. L</search_related> aliases it to the related result
2255 source name (and keeps C<me> referring to the original result set). The long
2256 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2257 (and make this method unnecessary).
2259 Thus it's currently necessary to use this method in predefined queries (see
2260 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2261 source alias of the current result set:
2263 # in a result set class
2265 my ($self, $user) = @_;
2267 my $me = $self->current_source_alias;
2269 return $self->search(
2270 "$me.modified" => $user->id,
2276 sub current_source_alias {
2279 return ($self->{attrs} || {})->{alias} || 'me';
2283 my ($self, $extra_join) = @_;
2284 my $source = $self->result_source;
2285 my $attrs = $self->{attrs};
2287 my $from = $attrs->{from}
2288 || [ { $attrs->{alias} => $source->from } ];
2290 my $seen = { %{$attrs->{seen_join}||{}} };
2292 my $join = ($attrs->{join}
2293 ? [ $attrs->{join}, $extra_join ]
2296 # we need to take the prefetch the attrs into account before we
2297 # ->resolve_join as otherwise they get lost - captainL
2298 my $merged = $self->_merge_attr( $join, $attrs->{prefetch} );
2302 ($join ? $source->resolve_join($merged, $attrs->{alias}, $seen) : ()),
2305 return ($from,$seen);
2308 sub _resolved_attrs {
2310 return $self->{_attrs} if $self->{_attrs};
2312 my $attrs = { %{ $self->{attrs} || {} } };
2313 my $source = $self->result_source;
2314 my $alias = $attrs->{alias};
2316 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2319 # build columns (as long as select isn't set) into a set of as/select hashes
2320 unless ( $attrs->{select} ) {
2322 ( ref($_) eq 'HASH' ) ? $_
2325 /^\Q${alias}.\E(.+)$/ ? $1
2327 ) => ( /\./ ? $_ : "${alias}.$_" )
2329 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2331 # add the additional columns on
2332 foreach ( 'include_columns', '+columns' ) {
2333 push @colbits, map {
2334 ( ref($_) eq 'HASH' )
2336 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2337 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2340 # start with initial select items
2341 if ( $attrs->{select} ) {
2343 ( ref $attrs->{select} eq 'ARRAY' )
2344 ? [ @{ $attrs->{select} } ]
2345 : [ $attrs->{select} ];
2349 ref $attrs->{as} eq 'ARRAY'
2350 ? [ @{ $attrs->{as} } ]
2353 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2358 # otherwise we intialise select & as to empty
2359 $attrs->{select} = [];
2363 # now add colbits to select/as
2364 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2365 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2368 if ( $adds = delete $attrs->{'+select'} ) {
2369 $adds = [$adds] unless ref $adds eq 'ARRAY';
2371 @{ $attrs->{select} },
2372 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2375 if ( $adds = delete $attrs->{'+as'} ) {
2376 $adds = [$adds] unless ref $adds eq 'ARRAY';
2377 push( @{ $attrs->{as} }, @$adds );
2380 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2382 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2383 my $join = delete $attrs->{join} || {};
2385 if ( defined $attrs->{prefetch} ) {
2386 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2390 $attrs->{from} = # have to copy here to avoid corrupting the original
2392 @{ $attrs->{from} },
2393 $source->resolve_join(
2394 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2400 $attrs->{group_by} ||= $attrs->{select}
2401 if delete $attrs->{distinct};
2402 if ( $attrs->{order_by} ) {
2403 $attrs->{order_by} = (
2404 ref( $attrs->{order_by} ) eq 'ARRAY'
2405 ? [ @{ $attrs->{order_by} } ]
2406 : [ $attrs->{order_by} ]
2410 $attrs->{order_by} = [];
2413 my $collapse = $attrs->{collapse} || {};
2414 if ( my $prefetch = delete $attrs->{prefetch} ) {
2415 $prefetch = $self->_merge_attr( {}, $prefetch );
2417 my $seen = { %{ $attrs->{seen_join} || {} } };
2418 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2420 # bring joins back to level of current class
2422 $source->resolve_prefetch( $p, $alias, $seen, \@pre_order, $collapse );
2423 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2424 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2426 push( @{ $attrs->{order_by} }, @pre_order );
2428 $attrs->{collapse} = $collapse;
2430 if ( $attrs->{page} ) {
2431 $attrs->{offset} ||= 0;
2432 $attrs->{offset} += ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2435 return $self->{_attrs} = $attrs;
2439 my ($self, $attr) = @_;
2441 if (ref $attr eq 'HASH') {
2442 return $self->_rollout_hash($attr);
2443 } elsif (ref $attr eq 'ARRAY') {
2444 return $self->_rollout_array($attr);
2450 sub _rollout_array {
2451 my ($self, $attr) = @_;
2454 foreach my $element (@{$attr}) {
2455 if (ref $element eq 'HASH') {
2456 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2457 } elsif (ref $element eq 'ARRAY') {
2458 # XXX - should probably recurse here
2459 push( @rolled_array, @{$self->_rollout_array($element)} );
2461 push( @rolled_array, $element );
2464 return \@rolled_array;
2468 my ($self, $attr) = @_;
2471 foreach my $key (keys %{$attr}) {
2472 push( @rolled_array, { $key => $attr->{$key} } );
2474 return \@rolled_array;
2477 sub _calculate_score {
2478 my ($self, $a, $b) = @_;
2480 if (ref $b eq 'HASH') {
2481 my ($b_key) = keys %{$b};
2482 if (ref $a eq 'HASH') {
2483 my ($a_key) = keys %{$a};
2484 if ($a_key eq $b_key) {
2485 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2490 return ($a eq $b_key) ? 1 : 0;
2493 if (ref $a eq 'HASH') {
2494 my ($a_key) = keys %{$a};
2495 return ($b eq $a_key) ? 1 : 0;
2497 return ($b eq $a) ? 1 : 0;
2503 my ($self, $orig, $import) = @_;
2505 return $import unless defined($orig);
2506 return $orig unless defined($import);
2508 $orig = $self->_rollout_attr($orig);
2509 $import = $self->_rollout_attr($import);
2512 foreach my $import_element ( @{$import} ) {
2513 # find best candidate from $orig to merge $b_element into
2514 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2515 foreach my $orig_element ( @{$orig} ) {
2516 my $score = $self->_calculate_score( $orig_element, $import_element );
2517 if ($score > $best_candidate->{score}) {
2518 $best_candidate->{position} = $position;
2519 $best_candidate->{score} = $score;
2523 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2525 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2526 push( @{$orig}, $import_element );
2528 my $orig_best = $orig->[$best_candidate->{position}];
2529 # merge orig_best and b_element together and replace original with merged
2530 if (ref $orig_best ne 'HASH') {
2531 $orig->[$best_candidate->{position}] = $import_element;
2532 } elsif (ref $import_element eq 'HASH') {
2533 my ($key) = keys %{$orig_best};
2534 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2537 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2547 $self->_source_handle($_[0]->handle);
2549 $self->_source_handle->resolve;
2553 =head2 throw_exception
2555 See L<DBIx::Class::Schema/throw_exception> for details.
2559 sub throw_exception {
2561 if (ref $self && $self->_source_handle->schema) {
2562 $self->_source_handle->schema->throw_exception(@_)
2569 # XXX: FIXME: Attributes docs need clearing up
2573 Attributes are used to refine a ResultSet in various ways when
2574 searching for data. They can be passed to any method which takes an
2575 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2578 These are in no particular order:
2584 =item Value: ( $order_by | \@order_by | \%order_by )
2588 Which column(s) to order the results by. If a single column name, or
2589 an arrayref of names is supplied, the argument is passed through
2590 directly to SQL. The hashref syntax allows for connection-agnostic
2591 specification of ordering direction:
2593 For descending order:
2595 order_by => { -desc => [qw/col1 col2 col3/] }
2597 For explicit ascending order:
2599 order_by => { -asc => 'col' }
2601 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2602 supported, although you are strongly encouraged to use the hashref
2603 syntax as outlined above.
2609 =item Value: \@columns
2613 Shortcut to request a particular set of columns to be retrieved. Each
2614 column spec may be a string (a table column name), or a hash (in which
2615 case the key is the C<as> value, and the value is used as the C<select>
2616 expression). Adds C<me.> onto the start of any column without a C<.> in
2617 it and sets C<select> from that, then auto-populates C<as> from
2618 C<select> as normal. (You may also use the C<cols> attribute, as in
2619 earlier versions of DBIC.)
2625 =item Value: \@columns
2629 Indicates additional columns to be selected from storage. Works the same
2630 as L</columns> but adds columns to the selection. (You may also use the
2631 C<include_columns> attribute, as in earlier versions of DBIC). For
2634 $schema->resultset('CD')->search(undef, {
2635 '+columns' => ['artist.name'],
2639 would return all CDs and include a 'name' column to the information
2640 passed to object inflation. Note that the 'artist' is the name of the
2641 column (or relationship) accessor, and 'name' is the name of the column
2642 accessor in the related table.
2644 =head2 include_columns
2648 =item Value: \@columns
2652 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2658 =item Value: \@select_columns
2662 Indicates which columns should be selected from the storage. You can use
2663 column names, or in the case of RDBMS back ends, function or stored procedure
2666 $rs = $schema->resultset('Employee')->search(undef, {
2669 { count => 'employeeid' },
2674 When you use function/stored procedure names and do not supply an C<as>
2675 attribute, the column names returned are storage-dependent. E.g. MySQL would
2676 return a column named C<count(employeeid)> in the above example.
2682 Indicates additional columns to be selected from storage. Works the same as
2683 L</select> but adds columns to the selection.
2691 Indicates additional column names for those added via L</+select>. See L</as>.
2699 =item Value: \@inflation_names
2703 Indicates column names for object inflation. That is, C<as>
2704 indicates the name that the column can be accessed as via the
2705 C<get_column> method (or via the object accessor, B<if one already
2706 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2708 The C<as> attribute is used in conjunction with C<select>,
2709 usually when C<select> contains one or more function or stored
2712 $rs = $schema->resultset('Employee')->search(undef, {
2715 { count => 'employeeid' }
2717 as => ['name', 'employee_count'],
2720 my $employee = $rs->first(); # get the first Employee
2722 If the object against which the search is performed already has an accessor
2723 matching a column name specified in C<as>, the value can be retrieved using
2724 the accessor as normal:
2726 my $name = $employee->name();
2728 If on the other hand an accessor does not exist in the object, you need to
2729 use C<get_column> instead:
2731 my $employee_count = $employee->get_column('employee_count');
2733 You can create your own accessors if required - see
2734 L<DBIx::Class::Manual::Cookbook> for details.
2736 Please note: This will NOT insert an C<AS employee_count> into the SQL
2737 statement produced, it is used for internal access only. Thus
2738 attempting to use the accessor in an C<order_by> clause or similar
2739 will fail miserably.
2741 To get around this limitation, you can supply literal SQL to your
2742 C<select> attibute that contains the C<AS alias> text, eg:
2744 select => [\'myfield AS alias']
2750 =item Value: ($rel_name | \@rel_names | \%rel_names)
2754 Contains a list of relationships that should be joined for this query. For
2757 # Get CDs by Nine Inch Nails
2758 my $rs = $schema->resultset('CD')->search(
2759 { 'artist.name' => 'Nine Inch Nails' },
2760 { join => 'artist' }
2763 Can also contain a hash reference to refer to the other relation's relations.
2766 package MyApp::Schema::Track;
2767 use base qw/DBIx::Class/;
2768 __PACKAGE__->table('track');
2769 __PACKAGE__->add_columns(qw/trackid cd position title/);
2770 __PACKAGE__->set_primary_key('trackid');
2771 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2774 # In your application
2775 my $rs = $schema->resultset('Artist')->search(
2776 { 'track.title' => 'Teardrop' },
2778 join => { cd => 'track' },
2779 order_by => 'artist.name',
2783 You need to use the relationship (not the table) name in conditions,
2784 because they are aliased as such. The current table is aliased as "me", so
2785 you need to use me.column_name in order to avoid ambiguity. For example:
2787 # Get CDs from 1984 with a 'Foo' track
2788 my $rs = $schema->resultset('CD')->search(
2791 'tracks.name' => 'Foo'
2793 { join => 'tracks' }
2796 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2797 similarly for a third time). For e.g.
2799 my $rs = $schema->resultset('Artist')->search({
2800 'cds.title' => 'Down to Earth',
2801 'cds_2.title' => 'Popular',
2803 join => [ qw/cds cds/ ],
2806 will return a set of all artists that have both a cd with title 'Down
2807 to Earth' and a cd with title 'Popular'.
2809 If you want to fetch related objects from other tables as well, see C<prefetch>
2812 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
2818 =item Value: ($rel_name | \@rel_names | \%rel_names)
2822 Contains one or more relationships that should be fetched along with
2823 the main query (when they are accessed afterwards the data will
2824 already be available, without extra queries to the database). This is
2825 useful for when you know you will need the related objects, because it
2826 saves at least one query:
2828 my $rs = $schema->resultset('Tag')->search(
2837 The initial search results in SQL like the following:
2839 SELECT tag.*, cd.*, artist.* FROM tag
2840 JOIN cd ON tag.cd = cd.cdid
2841 JOIN artist ON cd.artist = artist.artistid
2843 L<DBIx::Class> has no need to go back to the database when we access the
2844 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2847 Simple prefetches will be joined automatically, so there is no need
2848 for a C<join> attribute in the above search.
2850 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2851 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2852 with an accessor type of 'single' or 'filter'). A more complex example that
2853 prefetches an artists cds, the tracks on those cds, and the tags associted
2854 with that artist is given below (assuming many-to-many from artists to tags):
2856 my $rs = $schema->resultset('Artist')->search(
2860 { cds => 'tracks' },
2861 { artist_tags => 'tags' }
2867 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
2868 attributes will be ignored.
2878 Makes the resultset paged and specifies the page to retrieve. Effectively
2879 identical to creating a non-pages resultset and then calling ->page($page)
2882 If L<rows> attribute is not specified it defualts to 10 rows per page.
2884 When you have a paged resultset, L</count> will only return the number
2885 of rows in the page. To get the total, use the L</pager> and call
2886 C<total_entries> on it.
2896 Specifes the maximum number of rows for direct retrieval or the number of
2897 rows per page if the page attribute or method is used.
2903 =item Value: $offset
2907 Specifies the (zero-based) row number for the first row to be returned, or the
2908 of the first row of the first page if paging is used.
2914 =item Value: \@columns
2918 A arrayref of columns to group by. Can include columns of joined tables.
2920 group_by => [qw/ column1 column2 ... /]
2926 =item Value: $condition
2930 HAVING is a select statement attribute that is applied between GROUP BY and
2931 ORDER BY. It is applied to the after the grouping calculations have been
2934 having => { 'count(employee)' => { '>=', 100 } }
2940 =item Value: (0 | 1)
2944 Set to 1 to group by all columns.
2950 Adds to the WHERE clause.
2952 # only return rows WHERE deleted IS NULL for all searches
2953 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2955 Can be overridden by passing C<{ where => undef }> as an attribute
2962 Set to 1 to cache search results. This prevents extra SQL queries if you
2963 revisit rows in your ResultSet:
2965 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2967 while( my $artist = $resultset->next ) {
2971 $rs->first; # without cache, this would issue a query
2973 By default, searches are not cached.
2975 For more examples of using these attributes, see
2976 L<DBIx::Class::Manual::Cookbook>.
2982 =item Value: \@from_clause
2986 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2987 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2990 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2992 C<join> will usually do what you need and it is strongly recommended that you
2993 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2994 And we really do mean "cannot", not just tried and failed. Attempting to use
2995 this because you're having problems with C<join> is like trying to use x86
2996 ASM because you've got a syntax error in your C. Trust us on this.
2998 Now, if you're still really, really sure you need to use this (and if you're
2999 not 100% sure, ask the mailing list first), here's an explanation of how this
3002 The syntax is as follows -
3005 { <alias1> => <table1> },
3007 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3008 [], # nested JOIN (optional)
3009 { <table1.column1> => <table2.column2>, ... (more conditions) },
3011 # More of the above [ ] may follow for additional joins
3018 ON <table1.column1> = <table2.column2>
3019 <more joins may follow>
3021 An easy way to follow the examples below is to remember the following:
3023 Anything inside "[]" is a JOIN
3024 Anything inside "{}" is a condition for the enclosing JOIN
3026 The following examples utilize a "person" table in a family tree application.
3027 In order to express parent->child relationships, this table is self-joined:
3029 # Person->belongs_to('father' => 'Person');
3030 # Person->belongs_to('mother' => 'Person');
3032 C<from> can be used to nest joins. Here we return all children with a father,
3033 then search against all mothers of those children:
3035 $rs = $schema->resultset('Person')->search(
3038 alias => 'mother', # alias columns in accordance with "from"
3040 { mother => 'person' },
3043 { child => 'person' },
3045 { father => 'person' },
3046 { 'father.person_id' => 'child.father_id' }
3049 { 'mother.person_id' => 'child.mother_id' }
3056 # SELECT mother.* FROM person mother
3059 # JOIN person father
3060 # ON ( father.person_id = child.father_id )
3062 # ON ( mother.person_id = child.mother_id )
3064 The type of any join can be controlled manually. To search against only people
3065 with a father in the person table, we could explicitly use C<INNER JOIN>:
3067 $rs = $schema->resultset('Person')->search(
3070 alias => 'child', # alias columns in accordance with "from"
3072 { child => 'person' },
3074 { father => 'person', -join_type => 'inner' },
3075 { 'father.id' => 'child.father_id' }
3082 # SELECT child.* FROM person child
3083 # INNER JOIN person father ON child.father_id = father.id
3085 If you need to express really complex joins or you need a subselect, you
3086 can supply literal SQL to C<from> via a scalar reference. In this case
3087 the contents of the scalar will replace the table name asscoiated with the
3090 WARNING: This technique might very well not work as expected on chained
3091 searches - you have been warned.
3093 # Assuming the Event resultsource is defined as:
3095 MySchema::Event->add_columns (
3098 is_auto_increment => 1,
3107 MySchema::Event->set_primary_key ('sequence');
3109 # This will get back the latest event for every location. The column
3110 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3111 # combo to limit the resultset
3113 $rs = $schema->resultset('Event');
3114 $table = $rs->result_source->name;
3115 $latest = $rs->search (
3118 (SELECT e1.* FROM $table e1
3120 ON e1.location = e2.location
3121 AND e1.sequence < e2.sequence
3122 WHERE e2.sequence is NULL
3127 # Equivalent SQL (with the DBIC chunks added):
3129 SELECT me.sequence, me.location, me.type FROM
3130 (SELECT e1.* FROM events e1
3132 ON e1.location = e2.location
3133 AND e1.sequence < e2.sequence
3134 WHERE e2.sequence is NULL
3141 =item Value: ( 'update' | 'shared' )
3145 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT